U.S. patent number 6,120,222 [Application Number 08/924,206] was granted by the patent office on 2000-09-19 for machine tool.
This patent grant is currently assigned to Makino Milling Machine, Co., Ltd.. Invention is credited to Hiromi Hara, Kazuyuki Hiramoto, Naoshi Takayama, Naozumi Tanikawa.
United States Patent |
6,120,222 |
Hiramoto , et al. |
September 19, 2000 |
Machine tool
Abstract
To provide a compact size machine tool free from the
inconveniences inherent to the prior art and excellent in the
collection and removal of chips or the like, there is provided a
channel 39 in a central portion of the bed 3 directly beneath the
table 21 and extending parallel to the table moving direction; a
chip conveyor 47 being provided inside the channel 39; on both
sides with respect to the channel 39, a pair of opposite slopes 51,
51 for collection of chips as well as telescopic covers 53, 53
extensible or contractible in accordance with the displacement of
the table 21 being provided so as to cover a pair of guide rails
13, 13 which extend parallel to each other along the Z
direction.
Inventors: |
Hiramoto; Kazuyuki (Yamanashi,
JP), Takayama; Naoshi (Yamanashi, JP),
Hara; Hiromi (Yamanashi, JP), Tanikawa; Naozumi
(Yamanashi, JP) |
Assignee: |
Makino Milling Machine, Co.,
Ltd. (Tokyo, JP)
|
Family
ID: |
14111921 |
Appl.
No.: |
08/924,206 |
Filed: |
September 5, 1997 |
Foreign Application Priority Data
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Mar 31, 1997 [JP] |
|
|
9-094496 |
|
Current U.S.
Class: |
409/134;
409/137 |
Current CPC
Class: |
B23Q
11/0042 (20130101); B23Q 11/08 (20130101); Y10T
409/30392 (20150115); Y10T 409/304088 (20150115) |
Current International
Class: |
B23Q
11/00 (20060101); B23Q 11/08 (20060101); B23Q
011/08 () |
Field of
Search: |
;409/134,137 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2634255 |
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Feb 1978 |
|
DE |
|
223970 |
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Jun 1978 |
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DE |
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34 16 429 |
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Nov 1985 |
|
DE |
|
58-93437 |
|
Jun 1983 |
|
JP |
|
61-103754 |
|
May 1986 |
|
JP |
|
61-120448 |
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Jul 1986 |
|
JP |
|
62113948 |
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Jul 1987 |
|
JP |
|
6-28835 |
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Mar 1988 |
|
JP |
|
4-283041 |
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Oct 1992 |
|
JP |
|
6-091457 |
|
Apr 1994 |
|
JP |
|
2 095 141 |
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Sep 1982 |
|
GB |
|
Other References
Patent Abstract of Japan, vol. 018, No. 354 (M-1632) Jul. 5, 1994
(JP 06-091457 Apr. 5, 1994 Okuma Mach Works Ltd.)..
|
Primary Examiner: Howell; Daniel W.
Attorney, Agent or Firm: McAulay Nissen Goldberg Kiel &
Hand, LLP
Claims
What is claimed is:
1. A machine tool, for machining a workpiece by a relative
displacement between the workpiece and a tool in three axial
directions X, Y, and Z, comprising:
a bed forming a base;
a table, on which the workpiece is secured, which is guided and
movable on the bed in at least a horizontal direction by a pair of
opposed table-guides;
a spindle head having a main spindle for mounting the tool, which
is relatively movable with respect to the table;
a U-shaped chip receiver forming a center trough for chips provided
under the table and extending in the table moving direction;
two covers, each of which covers one table-guide for the pair of
opposed table guides, for guiding and gathering chips into the chip
receiver; and
an adjustable cover composed of partially overlapping, relatively
movable cover plates and defining a rear surface of a splash guard
opposed to a frontal surface of a movable column, wherein said
adjustable cover has a through-hole through which the spindle head
or the movable column extends into the machining zone inside the
splash guard, said through-hole being able to change its position
so as to follow the movement of the spindle head in leftward and
rightward directions or in upward and downward directions.
2. A machine tool, for machining a workpiece by a relative
displacement between the workpiece and a tool in three axial
directions X, Y, and Z, comprising:
a bed forming a base;
a table, on which the workpiece is secured, which is guided and
movable on the bed in at least a horizontal direction by a pair of
opposed table-guides;
a horizontal type spindle head having a horizontally extending main
spindle for mounting the tool, which is relatively movable with
respect to the table;
a U-shaped chip receiver forming a center trough for chips provided
under the table and extending in the table moving direction;
two covers, each of which covers one table-guide for the pair of
opposed table-guides, for guiding and gathering chips into the chip
receiver;
a chip discharger disposed in the chip receiver, for conveying the
chips gathered in the chip receiver outside of the machine; and
an adjustable cover composed of partially overlapping, relatively
movable cover plates and defining a rear surface of a splash guard
opposed to a frontal surface of a movable column, wherein said
adjustable cover has a through-hole through which the spindle head
or the movable column extends into the machining zone inside the
splash guard, said through-hole being able to change its position
so as to follow the movement of the spindle head in leftward and
rightward directions or in upward and downward directions.
3. A machine tool, for machining a workpiece by a relative
displacement between the workpiece and a tool in three axial
directions X, Y, and Z, comprising:
a bed forming a base;
a column guided and movable leftward and rightward by a
column-guide provided on a rear portion of the bed;
a table, on which the workpiece is secured, which is guided and
movable forward and rearward by a pair of opposed table-guides
provided on a front portion of the bed;
a horizontal type spindle head having a horizontally extending main
spindle for mounting the tool, which is guided and movable up and
down by a head-guide;
a U-shaped chip receiver forming a center trough for chips provided
directly under the table and extending in the table moving
direction;
two covers, each of which covers one table-guide for the pair of
opposed table-guides, for guiding and gathering chips in to the
chip receiver;
a chip discharger disposed in the chip receiver, for conveying the
chips gathered in the chip receiver outside of the machine; and
an adjustable cover comprising partially overlapping, relatively
movable cover plates and defining a rear surface of the splash
guard opposed to a frontal surface of the column, wherein said
adjustable cover has a through-hole through which the spindle head
extends from the frontal surface of the column into the machining
zone inside the splash guard, said through-hole being able to
change its position so as to follow the movement of the spindle
head in a leftward and rightward direction and in an upward and
downward direction.
4. A machine tool, for machining a workpiece by a relative
displacement between the workpiece and a tool in three axial
directions X, Y, and Z, comprising:
a bed forming a base;
a column guided and movable leftward and rightward by a
column-guide provided on a rear portion of the bed;
a table, on which the workpiece is secured, which is guided and
moveable forward and rearward by a pair of opposed table-guides
provided on a front portion of the bed;
a horizontal type spindle head having a horizontally extending main
spindle for mounting the tool, which is guided and movable up and
down by a head-guide;
a splash guard for covering a machining zone for the workpiece,
having a pair of opposed slopes in a lower part thereof for
enhancing the movement of the chips;
a U-shaped chip receiver for the chips provided on a central
portion of the bed under the table and extending in a forward and
rearward direction;
two pairs of extendable/retractable covers working in accordance
with the displacement of the table, each pair of which covers one
table-guide for the pair of opposed table-guides to prevent the
chips entering;
a chip discharger disposed in the chip receiver, for conveying to
the outside of the machine the chips which have fallen down into
the chip receiver; and
an adjustable cover comprising partially overlapping, relatively
movable cover plates and defining a rear surface of the splash
guard opposed to a frontal surface of the column, wherein said
adjustable cover has a through-hole through which the spindle head
extends from the frontal surface of the column into the machining
zone inside the splash guard, said through-hole being able to
change its position so as to follow the movement of the spindle
head in a leftward and rightward direction and in an upward and
downward direction.
5. The machine tool according to claim 4, including a table feeder
for moving the table in the forward and rearward direction provided
in front of the table, and wherein said chip discharger may
discharge the chips through a front side outlet of the chip
receiver.
6. The machine tool according to claim 1, wherein the column is
guided by a column guide on a rear portion of the bed.
7. The machine tool according to claim 4, wherein said cover plates
are composed of a stationary cover plate, an X cover plate, and a Y
cover plate which are put one on another in this order; the
stationary cover plate being fixed to a rear side wall of the
splash guard for covering an interface between the machining zone
and the column; the X cover plate being provided behind the
stationary cover plate to be movable in the leftward and rightward
direction together with the spindle head; and the Y cover plate
being provided behind the X cover plate to be movable in the upward
and downward direction together with the spindle head.
8. The machine tool according to claim 4, wherein said chip
receiver is made of a thin sheet member and fixed to the bed at
several points with a certain clearance between the chip receiver
and the bed.
9. The machine tool according to claim 1, including a chip
discharger disposed in the chip receiver, for conveying the chips
gathered in the chip receiver to the outside of the machine.
10. The machine tool according to claim 1, including a column
guided and movable leftward and rightward by a column-guide
provided on a rear portion of the bed.
11. The machine tool according to claim 1, wherein the spindle head
is a horizontal type spindle head and the main spindle is a
horizontally extending main spindle for mounting the tool which is
guided and movable up and down by a head guide.
12. The machine tool according to including claim 1, wherein the
opposed table-guides guide and move the table forward and rearward
and are provided on a front portion of the bed.
13. The machine tool according to claim 1, including a splash guard
for covering a machining zone for the workpiece, having a pair of
opposed slopes in a lower part thereof for enhancing the movement
of the chips.
14. The machine tool according to claim 1, including two pairs of
extendable and retractable covers working in accordance with the
displacement of the table, each pair of which covers one
table-guide for the pair of opposed table-guides to prevent the
chips entering.
15. The machine tool according to claim 1, wherein the U-shaped
chip receiver for the chips is provided on a central portion of the
bed under the table and extending in forward and rearward direction
of the table.
16. The machine tool according to claim 2, wherein a table feeder
for moving the table in a forward and rearward direction is
provided in front of the table, and wherein said chip discharger
may discharge the chips thorough a front side outlet of the chip
receiver.
17. A machine tool according to claim 1 further comprising a pair
of slopes, each of which are disposed above each of said covers for
covering the pair of opposed table guides, for guiding the chips
into the center trough.
18. The machine tool according to claim 1, wherein said cover
plates are composed of a stationary cover plate, an X cover plate,
and a Y cover plate which are put one on another in this order; the
stationary cover plate being fixed to a rear side wall of the
splash guard for covering an interface between the machining zone
and the column; the X cover plate being provided behind the
stationary cover plate to be movable in the leftward and rightward
directions together with the spindle head; and the Y cover plate
being provided behind the X cover plate to be movable in the upward
and downward direction together with the spindle head.
19. The machine tool according to claim 1, wherein said chip
receiver is made of a thin sheet member and fixed to the bed at
several points with a certain clearance between the chip receiver
and the bed.
20. The machine tool according to claim 2, wherein said chip
receiver is made of a thin sheet member and fixed to the bed at
several points with a certain clearance between the chip receiver
and the bed.
21. The machine tool according to claim 2, wherein said cover
plates are composed of a stationary cover plate, an X cover plate,
and a Y cover plate which are put one on another in this order; the
stationary cover plate being fixed to a rear side wall of the
splash guard for covering an interface between the machining zone
and the column; the X cover plate being provided behind the
stationary cover plate to be movable in the leftward and rightward
directions together with the spindle head; and the Y cover plate
being provided behind the X cover plate to be movable in the upward
and downward direction together with the spindle head.
22. A machine tool according to claim 1 further comprising means
for driving the table along the pair of opposed table guides, the
driving means including a ball screw extending parallel to the
table guides, a screw nut, secured to the table, for engaging the
ball screw, and a motor, connected to the front end of the ball
screw, for rotating the ball screw to control the movement of the
table.
23. A machine tool according to claim 1, further, wherein the
U-shaped chip remover comprises a chip conveyer extending parallel
to the table guides and including a pair of sprockets positioned at
the front and rear ends of the chip conveyer, an endless chain
wrapped around both the sprockets, and a plurality of scrapers,
oriented substantially perpendicular to the table guides and
arranged at a generally equal pitch along the chain.
24. A machine tool according to claim 23, wherein the chip remover
is adapted to move the chips disposed in the center through toward
the front end of the chip remover.
25. A machine tool according to claim 1, wherein the adjustable
cover is not movable in the direction parallel to the table guides
to define the rear surface of the splash guard.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a machine tool for machining a
workpiece with a relative displacement between the workpiece and a
tool in three dimensional directions X, Y, and Z.
2. Description of the Related Art
In the field of machine tools, how to effectively remove or
discharge a large amount of chips generated during machining is an
important problem. Up to now, several companies have carried out
research and development regarding this problem.
For examples, chip-removal structures are proposed, in Japanese
Examined Patent Publication (Kokoku) No. 6-28835 and Japanese
Unexamined Utility Model Publication (Kokai) No. 58-93437, wherein
channels are provided on both sides of a table so that chips are
separately received into the respective channel. In detail, the
former publication discloses a
chip-removal structure for a vertical type machining center wherein
channels are provided on both sides of a table movable in X/Y
directions so that chips are received by the respective channel and
discharged outside therefrom by a chip-discharging means provided
in the respective channel. The latter discloses a chip-removal
structure for a horizontal type machining center wherein channels
are provided on both sides of a table movable in Z direction so
that chips are received by the respective channel and conveyed
outside therefrom by a chip-discharging means by using a fluid
provided in the respective channel.
However, according to the above prior art structures, there is a
problem that the structure becomes complicated since the channels
are separately provided in two locations and need two independent
chip-discharging means respectively corresponding thereto. Also,
the width of the channel in connection with the total width of the
machining center is predetermined. In the prior arts, the channel
is split into two separate channels, and the width of each separate
channel is identical to one-half the predetermined width, thereby
preventing a smooth flow of chips from a workpiece being machined.
Consequently, a heap of chips (a nest-like pile of chips) is liable
to form in the respective channels. This tendency would be
enhanced, as the width of the machining center is reduced leading
to a reduction in the width of the channels.
SUMMARY OF THE INVENTION
An essential object of the present invention is to provide a
compact size machine tool having a stable and improved chip
collection/removal performance without the above-mentioned
drawbacks.
According to a first feature of the present invention, there is
provided a machine tool, for machining a workpiece by a relative
displacement between the workpiece and a tool in the three axial
directions X, Y, and Z, comprising: a bed forming a base; a table,
on which the workpiece is secured, which is guided and movable on
the bed in at least a horizontal direction by a pair of opposed
table-guides; a spindle head having a main spindle for mounting the
tool, which is relatively movable with respect to the table; a
U-shaped chip receiver for chips provided under the table and
extending in the table moving direction; and two covers, each of
which covers one of the pair of table-guides, for guiding and
gathering chips into the chip receiver.
According to a second feature of the present invention, there is
provided a machine tool, for machining a workpiece by a relative
displacement between the workpiece and a tool in the three axial
directions X, Y, and Z, comprising: a bed forming a base; a table,
on which the workpiece is secured, which is guided and movable on
the bed in at least a horizontal direction by a pair of opposed
table-guides; a horizontal type spindle head having a horizontally
extending main spindle for mounting the tool, which is relatively
movable with respect to the table; a U-shaped chip receiver for
chips provided under the table and extending in the table moving
direction; two covers, each of which covers one of the pair of
table-guides, for guiding and gathering chips into the chip
receiver; and a chip discharger disposed in the chip receiver, for
conveying the chips gathered in the chip receiver to the outside of
the machine.
According to a third feature of the present invention, there is
provided a machine tool, for machining a workpiece by a relative
displacement between the workpiece and a tool in the three axial
directions X, Y, and Z, comprising: a bed forming a base; a column
guided and movable leftward and rightward by a column-guide
provided on a rear portion of the bed; a table, on which the
workpiece is secured, which is guided and movable forward and
rearward by a pair of opposed table-guides provided on a front
portion of the bed; a horizontal type spindle head having a
horizontally extending main spindle for mounting the tool, which is
guided and movable up and down by a head-guide; a U-shaped chip
receiver for chips provided under the table and extending in the
table moving direction; two covers, each of which covers one of the
pair of table-guides, for guiding and gathering chips into the chip
receiver; and a chip discharger disposed in the chip receiver, for
conveying the chips gathered in the chip receiver to the outside of
the machine.
According to a fourth feature of the present invention, there is
provided a machine tool, for machining a workpiece by a relative
displacement between the workpiece and a tool in the three axial
directions X, Y, and Z, comprising: a bed forming a base; a column
guided and movable leftward and rightward by a column-guide
provided on a rear portion of the bed; a table, on which the
workpiece is secured, which is guided and movable forward and
rearward by a pair of opposed table-guides provided on a front
portion of the bed; a horizontal type spindle head having a
horizontally extending main spindle for mounting the tool, which is
guided and movable up and down by a head-guide; a splash guard for
covering a machining zone for the workpiece, having a pair of
opposed slopes in a lower part thereof for enhancing the movement
of the chips; a U-shaped chip receiver for chips provided on a
central portion of the bed under the table and extending in the
forward/rearward direction; two pairs of extendable/retractable
covers working in accordance with the displacement of the table,
each pair covering one of the pair of table-guides to prevent the
chips entering; and a chip discharger disposed in the chip
receiver, for conveying to the outside of the machine the chips
which have fallen down into the chip receiver.
According to the present invention, since the U-shaped chip
receiver is provided beneath the table and extends in the table
moving direction, chips generated during the machining of the
workpiece reliably fall down directly or along the sloped cover
portions into the chip receiver without disturbance. By means of
the chip discharger disposed in the chip receiver, the chips are
automatically conveyed to the outside of the machine without
delay.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects of the present invention will become
apparent from the following detailed description of the preferred
embodiments of the invention in connection with the accompanying
drawings.
In the drawings:
FIG. 1 is a side cross-sectional view taken along line I--I in FIG.
2, illustrating a horizontal type machining center according to a
preferred embodiment of the machine tool of the present
invention;
FIG. 2 is a frontal view, sectioned along line II--II in FIG. 1, of
the horizontal type machining center;
FIG. 3 is a frontal view, sectioned along line III--III in FIG. 1,
of the horizontal type machining center;
FIG. 4 is a side view, in partly sectioned, illustrating a vertical
type machining center.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described below, in detail, with
reference to the preferred embodiments.
FIG. 1 is a side sectional view (taken along line I--I of FIG. 2)
illustrating an overall structure of one embodiment of the present
invention wherein a machine tool 1 is of a horizontal type for
carrying out a desired machining operation on a workpiece by a
relative displacement between the workpiece and a tool in the three
axial directions X, Y and Z.
FIG. 2 is a sectional view taken along line II--II of FIG. 1, and
FIG. 3 is a sectional view taken along line III--III of FIG. 1.
In FIG. 1, a large size bed 3 having an L-shape, as a whole, with
an elevated rear portion is formed by a box-like hollow structure
supported by a plurality of ribs in the interior thereof for the
purpose of weight reduction while maintaining a necessary rigidity
and dimensional accuracy.
On a flat top of the rear portion of the bed 3, a pair of guide
rails extend in the X direction, on which a column 5 is mounted to
be movable in the X direction relative to the bed 3. On the front
vertical surface of the column 5, a pair of guide rails 7, 7 extend
in the Y direction, on which a spindle head 9 is mounted to be
movable in the Y direction relative to the column 5. A tool is
mounted to the spindle head 9, and a main spindle 11 is assembled
to the spindle head 9 to be rotatable around an axis parallel to
the Z axis.
A front portion of the bed 3 (i.e., a left side bed portion in FIG.
1) has a wide and horizontal flat surface. On both sides of the
flat surface as seen from a front side of the machine (see FIGS. 2
and 3) is provided a pair of guide rails 13, 13 which extend
parallel to each other along the Z direction. A table 13 is mounted
on the guide rails 13 to be movable in the Z direction. Onto the
table 21, a pallet 19 is detachably mounted via a
pallet-positioning device 23. The pallet 19 carries an angle plate
17 on which a workpiece 15 is detachably mounted opposite to the
tool.
As described, by means of the pallet-positioning device 23
interposed between the table 21 and the pallet 19, it is possible
to automatically secure the pallet 19 in a predetermined position
on the table 15 in a detachable manner by a pallet exchanger (not
shown), while maintaining the workpiece 15 and the angle plate 17
on the pallet 19. In other words, it is possible to exchange a
workpiece along with a pallet on which the former is mounted.
Of course, the angle plate 17 and the workpiece 15 are separately
attachable and detachable.
On the top of the front portion of the bed 3, a pair of brackets 25
and 27 are provided in the Z direction in a central area thereof,
between which a ball screw 29 extends in the Z direction and is
rotatably supported by bearings 31, 31 fitted in the brackets 25,
27. To drive the ball screw 29, a Z-axis feed motor 33 is provided
in front of the bracket 25 which is closer to the front side of the
bed 3.
On the bottom side of the table 21 is provided a nut bracket, into
which a feed-screw nut 37 is fitted. The feed-screw nut 37 and the
ball screw 29 extending through the former form a Z-axis feed means
for driving the table 21.
By driving the Z-axis motor 33 in a controlled manner, it is
possible to control the Z-axial feeding of the table 21 on the bed
3, and then, the Z-axial position of the workpiece 15 relative to
the main spindle 11.
With reference to FIG. 2, a movable, so-called telescopic cover 35
is provided for covering upper and lateral sides of the ball screw
29, having an inverse U-shaped cross-section with an open lower
side, in order to protect from chips the feed screw means, which is
exposed when the table moves in the Z direction. This open type
telescopic cover 35 is composed of a plurality of U-shaped plates
partially overlapping one another and is extendable or contractible
in the Z direction with almost no gaps between the plates.
When the bed 3 is seen from the front side, a channel (or U-shaped
chip receiver) 39 is provided via seats 41 in a recess formed on
the top of the front portion of the bed 3 between the pair of
Z-axial guide rails 13, 13. The channel 39 has a width and a depth
sufficient to accommodate a chip discharger (or chip-removal
means).
In this regard, a front end of the channel 39 does not exceed a
stepped rear side part of the bed 3 (see FIG. 1).
The chip discharger is accommodated within a bottom of the channel
39, which is constituted by a chip conveyor 47 comprising a pair of
sprockets positioned at front and rear ends thereof, an endless
chain 43 wrapped around both the sprockets, and a plurality of
scrapers 45 oriented in the X direction and arranged at a generally
equal pitch along the chain 43. The scrapers 45 are shaped so as to
close a gap formed between the bottom of the channel 39 and the
chain 43.
The seats 41 for isolating the channel 39 from the bed 3 create a
gap for preventing heat in the chips, a coolant, and the like
transported by the chip conveyor 47 from being conducted to the bed
3, thereby preventing generating of the thermal expansion strain
therein during the transportation.
A width of the channel 39 is generally equal to a distance between
telescopic covers 53 and 53 contiguous to the lower edges of a pair
of opposite slopes 51 and 51 attached to both sides of a splash
guard 49 described later. The channel 39 extends from a position in
front of the rear portion of the bed 3 to a position exceeding the
front end of the bed 3, and has a chip-discharging opening 55 on
the lower side of the front end thereof.
The channel 39 extends all over the area for receiving all chips to
be guided and collected by the slopes 51 and the telescopic covers
35, and the chip conveyor 47 is driven to rotate clockwise (see
FIG. 1) to transport the collected chips on the conveyor 47 to the
chip-discharging opening 55. A coolant tank 57 is located beneath
the chip-discharging opening 55 to receive the chips falling down
from the opening 55 together with the coolant.
The telescopic covers 53, 53 are a movable cover used for covering
spaces between the rear stepped portion of the bed 3 and the table
21 and between the table 21 and a front side plate of the splash
guard 49 described later to protect a slide surface of the table 21
from the chips of the workpiece, i.e., the Z-axial guide rails 13,
13 for the bed 3 and to guide the chips falling down onto the slope
51 to the chip conveyor 47.
With reference to FIGS. 1, 2 and 3, the splash guard 49 serves to
cover the machining zone of the workpiece 15, prevent the coolant
and/or chips from splashing outside, and protect the operator from
danger due to the rotation of tool and the scattering of chips.
The slopes 51, 51 described above are attached to the lower portion
of both lateral side walls of the splash guard 49 to prevent the
chips and/or the coolant from falling down on the Z-axial guide
rails 13, 13 of the bed 3. By increasing the inclination angle of
the slopes 51, 51, the dwelling of chips on the slope can be
eliminated.
A portion of the rear side wall of the splash guard 49 through
which the spindle head 9 extends has a triple-layered window
structure consisting of an XY cover 59, an X cover 61 and a Y cover
63.
With reference to FIG. 3, the XY cover 59 is fixed to a rear side
wall of the splash guard 49 (constituting a part of a main body of
the splash guard 49), and has a generally rectangular through-hole
59a. Behind the XY cover 59 (on a rear surface as seen from the
front side of the machine), the X cover 61 is provided to cover a
central portion of the through-hole 59a, and has an elongated
through-hole 61a. Behind the X cover 61, the Y cover 63 is provided
to cover a central portion of the through-hole 61a, and is
penetrated by the spindle head 9 at a center thereof.
Between each of left/right ends of the X cover 61 and each of
stationary plates 61c, 61c, each of movable covers 61b, 61b such as
a bellows or a telescopic cover is attached. Similarly, between
each of upper/lower ends of the Y cover 63 and each of stationary
plates 63b, 63b, each of movable covers 63a, 63a is attached.
Thus, the through-hole 59a defining a movable range of the spindle
head 9 in the X direction is always covered with the X cover 61 and
the movable covers 61b, 61b. The through-hole 61a defining a
movable range of the spindle head 9 in the Y direction is always
covered with the Y cover 63 and the movable cover 63a, 63a.
Therefore, the spindle head 9 is engaged in the relative movement
in the X and Y directions with no interference of the outer
circumference of the spindle head 9 with the inner peripheral edge
of the through-holes 59a, 61a.
According to such an arrangement, the spindle head 9 is movable in
the X and Y directions within the through-hole 59a of the XY cover
59. For this purpose, it is sufficient to form the through-hole 59a
to have a minimum size for the movable range of the spindle head 9
in the X and Y directions. Also, if forming four corners of the
through-hole in round shapes, the size thereof may be further
reduced. This results in the possibility of increase in the
inclination angle of the slopes 51, 51 to further facilitate the
prevention of heaping of chips. In this regard, since the XY cover
59, X cover 61, and Y cover 63 are of a thin plate-shape, the chips
hardly heap up on the inner peripheral edges of the through-holes
59a and 61a.
Referring now to FIG. 4, a supplemental embodiment of a vertical
type
machining center will be described, in which the same reference
numerals are used for designating the same or similar parts to
those in the horizontal machining center described and illustrated
in FIG. 1.
On the top of a front portion of an L-shaped bed 3 beneath a table
21 of the vertical type machining center is provided a channel 39
incorporating a chip discharger therein, the channel 39 being
arranged in the left/right directions as seen in the drawing so
that a chip-discharging opening of the chip discharger is
positioned at a front end of the bed 3. Also, a drive means for the
forward/rearward displacement of the table 21 is provided at the
front end of the bed 3. Regarding slopes, telescopic covers or
others for collecting chips, the explanation thereof will be
eliminated herein but is substantially the same as in the
above-described horizontal machining center.
In this way, it is possible to apply to a vertical type machining
center the same technical means as those of the horizontal type
machining center, and the operation and effect derived therefrom
are also the same as in the horizontal type machining center
described above.
In the above described embodiments of the present inventions,
various effects which could not be expected by the conventional
devices are achievable; in that, since the splash guard having
slopes and the telescopic cover extensible and contractible in the
horizontal direction are provided, the chips are prevented from
entering a gap between cover members; since the chips are
discharged from the front side of the machine, it is unnecessary to
provide a through-hole in the interior of the back side of the bed,
whereby the desired rigidity can be maintained in the bed; since
the feed means for feeding the table in the forward/rearward
directions, such as a ball screw or a drive motor is provided in
the front portion of the machine, it is unnecessary to provide a
through-hole in the interior of the back side of the bed, whereby
the desired rigidity can be maintained in the bed.
As described above, according to the present invention, since the
U-shaped chip receiver is provided beneath the table and extends in
the table moving direction, chips generated during the machining of
the workpiece reliably fall down directly or along the sloped cover
portions into the chip receiver without disturbance.
Especially, in horizontal type machining center, almost of all
chips may fall down through the open space between the table and
the column.
Further, by means of the chip discharger provided in the channel,
the chips may be automatically discharged outside of the machine.
To achieve the intended objectives, it is sufficient to provide a
single wide channel beneath the table, and, as a result thereof, a
reasonable machining center which is small in size and simple in
structure can be obtained.
It is to be understood that the present invention is by no means
limited to the specific embodiments as illustrated and described
herein, and that various modifications thereof may be made which
come within the scope of the present invention as defined in the
appended claims.
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